Robbie Grossman has probably been the biggest success story the Pirates have in the minors this season. The 21-year old outfielder was drafted in the 6th round of the 2008 draft and was lured away from the University of Texas thanks in large part to a $1 million signing bonus.

Grossman struggled his first two seasons in the low levels due to a large amount of strikeouts. He struck out 164 times at A-West Virginia in 2009 and cut that number to 118 as a 20-year old at A+ Bradenton in 2010. What was always intriguing, though is that Grossman always showed great ability to get on base by drawing a large amount of walks.

This year, though, Grossman has truly had a break out year and is currently sporting a .290/.429/.426 line. Yup, you saw that OBP correctly, .429. He’s cut down on his strikeouts even more (84) and he sits at 94 walks on the year. He’s also starting to show some power as he has hit 8 homers this year to go along with 24 doubles.

I was pretty excited to see Grossman for the first time in person on a road game for Bradenton in Clearwater against super prospect Jarred Cosart, who would be traded to the Astros the next day as the main part of the Hunter Pence deal.

It wasn’t the best day for Grossman at the plate. However, he did draw a walk (4th AB) to extend his on-base streak to 25 games. Here are videos of every Grossman plate appearance from that day:

Expect to hear a lot about Grossman next year as he makes the jump to AA as a 22-year old. His performance so far this year probably propels him as a top 10 prospect within the organization and is probably either the 3rd or 4th highest rated position along with Matt Curry behind both Starling Marte and Tony Sanchez.